THIS invention relates to the treatment of aqueous media and solid organic material to remove constituents which are hazardous or toxic to humans or the environment.
Conveyancing pipes or ducts used in conventional aqueous media treatment systems are not specifically engineered to effect any treatment, and consequently very little effective treatment occurs inside most pipes leading to or from treatment systems despite the fact that the pipes contribute substantially to the cost of the overall waste treatment system. In centralised sewerage treatment schemes the collection system can cost as much as the treatment plant to install. In a typical on-site treatment system for a single detached dwelling, 10 to 20 meters of 100 mm diameter pipework, or equivalent, leads to the treatment chamber, and a further 20 to 30 meters leads from the treatment chamber to the disposal/re-use area. Within the disposal area another 20 to 40 meters of pipe is commonly used in addition to trench support material, aggregate liners, and the like. Typically the treatment chamber is designed to be relatively large in order to provide sufficient retention time for treatment. Both aerobic and anaerobic treatment systems are typically bulky and deep in order to provide sufficient retention time for aqueous media treatment.
In sewered allotments there is much more than the equivalent of 60 meters of 100 mm diameter pipe, when a share of the common reticulation network is apportioned to each connection serviced
Aqueous media pipes have much to recommend them as aerobic treatment systems. They have a vented air space available above the aqueous media level most of the time, are usually out of sight, and are often installed in the ground or in buildings where the extremes of temperature are moderated.
A method of using a bed of decomposed and decomposing solid organic waste material to filter aqueous media is known and used commercially. The method uses a relatively deep bed thickness to effect the filtration. It also employs a technique where the filter bed is more or less evenly loaded. This results in some practical constraints.
1. The outlet drain for the treated water is considerably lower than the aqueous media inlet pipe. This often results in a need to pump the effluent where the land is fairly flat or where the water table is high. PA0 2. The bio-solids removed from the system are continually recontaminated, and pathogens are not deactivated before removal. PA0 3. Opportunity exists during heavy loading periods for the bed to be temporarily inundated since the aqueous media cannot flow anywhere else. This results in a less diverse community of breakdown organisms being able to survive under these circumstances. PA0 4. A treatment chamber with horizontally arranged long axis has a higher surface area than a vertically arranged treatment chamber.